my dog has all symptoms but the dex test neg

[guestnurse]

Recently had my 7 yr old mixed yorkie snauzzer mix tested using the 8 hr dexamethsone supression test my vet says my dog does NOT have cushings but he has all the symptoms. Dark skin on belly, pot belly, increased thirst and hunger, gain of 6lbs in 2 yrs, frequent urination having accidents in house when he never use to... What to do now? He was negative for diabetes.

[labblab]

Hello and welcome to our family! It would be great if you can post the actual numbers from your dog's LDDS test. That will give us better context for interpreting the test results. Also, are there any lab abnormalities that have cropped up? Cushing's dogs often exhibit a particular subset of blood and urine abnormalities: for example, elevated liver enzymes (especially ALKP), elevated cholesterol, dilute urine with abnormal specific gravity). How about thyroid level? Uncontrolled Cushing's itself can depress thyroid readings, but primary hypothyroidism could also be responsible for at least some of the symptoms you are seeing.

A negative result on the LDDS is usually a reliable rule-out for Cushing's. However, a small percentage of dogs who truly have the disease will present with a "false" negative on the test. In a situation where a dog otherwise exhibits a classic symptom profile, there may be value in performing an ACTH stimulation test:



When interpreting LDDS test results, first evaluate the eight-hour postdexamethasone administration cortisol concentration. If it is above the reference range, the dog probably has hyperadrenocorticism (false positive results may occur in dogs with nonadrenal illness). If it is within the reference range, either the dog does not have hyperadrenocorticism or there is a 5% to 10% chance that the dog has PDH. (The dog may have early pituitary disease and the pituitary gland is still responding to a pharmacologic dose of dexamethasone by decreasing ACTH production, thereby reducing serum cortisol concentrations.) In those cases, an ACTH stimulation test is warranted.


http://veterinarymedicine.dvm360.com/clinquiz-interpreting-low-dose-dexamethasone-suppression-test-results

In most cases, the ACTH stimulation test is administered as a test of cortisol level/reserves. However, it can be used to check the level of all the adrenal hormones in addition to cortisol. There is only one lab in the U.S. that can analyze the full profile: University of Tennessee at Knoxville. However, any vet can perform the required blood draws and then send the sample to Tennessee for analysis. In the face of a negative LDDS, it might be worth the bit of extra money to perform the full panel because it appears that elevations in adrenal hormones other than cortisol can be associated with similar symptoms.

Thanks in advance for any additional info you can give us about your dog's test results and overall medical history.

Marianne

[guestnurse]

thank you I will see if I can get the actual test results from my vet.

[molly muffin]

If the symptoms are there, and the LDDS is negative, I would probably have the ACTH test done, or maybe even an ultrasound. There is a 5% that will test negative on the LDDS from what I understand it has to do with placement of the pituitary tumor. Adrenal tumor dogs usually always test positive on the LDDS.

I know because we have been dealing with the same things for a long time, except that my dog doesn't have the usual symptoms of cushings. Drinking and peeing lots, ravenous hunger, hair loss, etc.

So that is what I would do. What did your vet suggest a next step to be?

Sharlene and molly muffin